Part 1 - Introduction
Welcome. We hope that this video will help science teachers perform an inventory of their laboratory chemicals. Encouraging
the practice of doing such an inventory each year is a major goal of EPA’s School Chemical Cleanout Campaign, or SC3 for short.
The SC3 program was started in 2004 and continued until 2010. The Florida Department of Environmental Protection, or DEP for
short, managed the program for EPA in Florida. About half the high schools in the state were visited and several hundred teachers
received training in chemical management. The SC3 program was a response to a history of accidents and incidents involving
chemicalsin schools. The goals of the program were to remove excess, unused, deteriorated, or out of date chemicals from
schools; to identify potentially dangerous chemicals that should not be present or used at all; ensure that all chemicals are
managed properly; encourage the removal of all mercury and mercury compounds from schools; and in general offer assistance to
schools to improve their chemical management procedures.
The first step in accomplishing these goals is to inventory the chemicals already present. Who should do this inventory? Only
someone who has technical knowledge about the nature of chemicals, and that is almost always the science teachers. It’s best to
have two people perform the inventory, but never a student. Depending upon the situation, a comprehensive inventory can take
anywhere from 15 minutes to two weeks to accomplish.
Before beginning the inventory it is a good idea to review which chemicals are high risk. There are several lists to consult,
and most of them are posted on DEP’s website. There is one called excessive risk chemicals, about 140, and may school districts
have banned the use of any chemical on this list, so you need to know if you have any of these chemicals. Another list is the high
risk chemicals, which although they are not banned, do require very special management and they should be kept in only small
amounts. And then there is Flinn’s “Devils List” of the 40 most problematic chemicals commonly found in schools, and we have
found most of the items on the “Devils List” in Florida schools.
Part 2 - Preparation
Ok, let’s get started. The first thing to do is to get dressed for the job. That is, for this, would include a chemical resistant
apron. I prefer an apron with pockets in it so I can keep my tools, or if you don’t have one like that you can always get a nail
apron from Lowes or Home Depot. They come in very handy. Of course you will need some safety glasses, and gloves. Gloves are very
important to wear whenever you’re handling chemicals. These are nitrile gloves, they are not resistant to all chemicals, but they do
a good job on most. Never use latex gloves when you’re handling chemicals, because they are virtually transparent to most chemicals.
If the inventory hasn’t been done in some years, a mirror is a good thing to have so that you don’t have to touch the container.
You can just orient the mirror so that you can see and read the label; you just have to learn to read backwards. Then, you’ll need
a sharp pencil. I prefer to do the inventory with a pencil because so often you will find another container of the same chemical in
another area of the store room. And, so that way you can modify the total amount.
This is the inventory list that DEP also has on its website, and you can download it. It has most of the chemicals that you are
likely to find in a high school or middle school situation. They have done it alphabetically, which is not the best way to organize
your chemical storage situation, but you can make your own inventory list whatever suits your purpose the best. I use the alphabetical
one because I come across all kinds of different storage techniques.
Part 3 – Inventory
When doing a chemical inventory, you need to look everywhere, and not just in the storage area itself. You need to look in the fume
hood, and desk drawers, refrigerators; you would be amazed at where you might find some chemicals. Some things I have noticed about
this particular storage area is that there are chemicals that are above eye level. That’s not a good idea, because I’m going to have
to use a little stool to be able to read the labels on these chemicals. Also, there is not posted any system for chemical organization
in this particular storage room, and there should be. You should have either a Flinn system which many teachers use, ChemSafe has a
system, Fisher does; it really doesn’t matter which one you use, but it should be used. It appears to me from just looking at these
chemicals that he has on the shelf that his is kind of a combination of hazard class and alphabetical order. Alphabetical order is not
a good system to organize chemicals, because you may well have incompatibles that are stored next to each other. Looking at this shelf
right here, I can see an example straight away. He has got powered zinc metal, which is highly flammable, stored on the same shelf as
sodium chlorate, which is a very powerful oxidizer, so they should never be stored together. In this case I would probably remove this
straight away to prevent any kind of incompatible reactions. I see that he also has some potassium nitrate on that shelf, and that’s
not a good thing. Alright, but I am going to get started doing this inventory. I’m using an inventory sheet that you can also get on
the DEP website. It is alphabetical order. It has most chemicals you are ever likely to see in a school storage area. If there is one
that is not on the list, you can just add it on the back page. And, to do this inventory, you just start very systematically and just
do them one at a time. Now, this kind of material that is commercial material is probably not necessary to inventory; like salt, baking
soda, and tenderizer. These are things that you can buy at Wal-Mart and they don’t need to be on your inventory list. Anything that came
from a chemical company should be noted, even if it is perfectly harmless. That’s the five zeros, we like to see that. That means that
this is a non hazardous chemical. But, we look on our list here and see Guar Gum, alright and there are one, two, three, four, five,
six containers, and the total amount is less than 20 grams. So, we note that on our inventory list. Number of containers is five, less
than 20 grams. Also, in this inventory list, it tells you what the hazard of the material is and in this case it’s non hazardous. Ok,
then we continue on, I don’t think we need to do the oats; sucrose 0.5 mil aqueous solution, so we go and we find sucrose. Ok, it doesn’t
have any solution mixtures listed, it just says sucrose and it notes that it is non hazardous. So we would just put there, one container
is all I see, and then note in parentheses 0.5 molar, and the amount is 120 mils. And so on, and here I notice already, we have some
miss-stored compounds. Managanese dioxide is an oxidizer and so it should be stored seperately from anything that is a reducer, anything
that is flammable. And here is an example of a container that is completely empty, so it should be discarded. Now these kits, these Flinn
kits, they have several chemicals in them, you need to note which each chemical is, separately, and if some need to be stored in a special
area, like in the flammable cabinet or the corrosive cabinet, that should be done. But we are going to mark them, there is formaldehyde
37# solution, okay that is a fairly high risk chemical. We might want to store that, it should be stored in the corrosive cabinet,
so we will make a note of that. And note that it is in a kit, so that you can find it when you need to use it.
I have noticed, when I did my first initial survey of this storage room, that there are a lot of oxidizers that are just mingled among other chemicals, and that’s a rather dangerous situation. So, I am going to go ahead and remove the oxidizers that are potent enough to cause problems. Here he has some hydrogen peroxide that’s 3#, that’s not a problem. That is diluted. But, he’s also got 29-30# hydrogen peroxide, which is a very powerful oxidizer, and it should be stored in a way that you aware of its hazard and keep it away of any material that is subject to being oxidized by such a potent oxidizer. So, I am going to take these out and put them in a better place. I see also, he has some potassium permanganate that’s also a potent oxidizer. And, back here he also has potassium nitrate, sodium chlorate stored with finely powered metal, which is a flammable solid, and that shouldn’t be. So, I am going to take these oxidizers, as well. Now, you can store oxidizers in the general open shelves, however it is a good idea to put them in some kind of secondary containment to prevent them from having contact with the wooden shelf, which is not a good thing. And also, if there are any spills, it’s much easier to clean them up if the container is in, like a dishpan. You can just buy them at Wal-Mart. Now, a solution of the nitrate, this is 0.1 molar, even though nitrates are oxidizers, something this diluted is not a hazard, and so it does not need to be handled so, separately.
Part 4 – Flammable Cabinet
The flammable cabinet is where you might find your major problems. Frequently there are chemicals in here that are high risk. Especially, keep in mind that there are some solvents that are called peroxide formers, and that means that when they get old and exposed to air, they will form peroxides that are extremely flammable and even explosive in some cases. The worst peroxide formers are ethyl ether, and cyclohexene; not cyclohexane, but cyclohexene. We have had several problems with those materials in high school storage areas. So, be careful when you’re going through the flammable cabinet. This is where you might need to use your mirror, in case there is an old bottle that you aren’t sure what it is. You don’t want to move or touch any of these bottles that are extremely old, because it is possible that they are peroxide formers. I am looking in this cabinet and it appears to be quite new and it’s in good condition. Now, if there’s rust; these little things will rust away and the shelves will collapse. This has happened, that’s a very serious situation. Just take a good pre-look, and see if you see anything that looks suspicious, and there is not in this particular cabinet; it looks as if everything is pretty new. I can read most of the labels without my mirror. I don’t think I am going to need it, but if I did it’s just a simple way of looking at it, you just hold it like that so you can read the label. You’ll learn how to read backwards.
Commonly, we will find oxidizers stored in the flammable cabinet, which is the worst possible place for them. Because, even though under the DOT regulations, flammable materials and oxidizers are considered the same class, they are incompatible. So, oxidizers should never be stored with flammables. And, I see here on the other side, just on the other side of the flammable cabinet there are some indicator solutions that are dissolved in alcohol, so they are flammable. These materials need to be kept in the flammable cabinet.
Part 5 – Corrosive Cabinet
This cabinet is their corrosive cabinet, but it’s not marked; it should be marked as “acid”. And it’s best if you can have two cabinets, one for acid and one for bases, but if you have only one, then store acids in it. Here again, this is a common source of problems; they use to make acid cabinets out of metal, and of course they deteriorated pretty rapidly. So, you need to check the condition of your acid cabinet to make sure that if it is metal that the little struts holding up the shelves haven’t rusted away, because this can cause a real serious problem when the acids fall and mix together; particularly if you have incompatibles in your acid cabinet.
So, let’s look in here. He has hydrochloric acid, six molar, that’s a good place for it. Okay, I see a problem already. He’s got vinegar, but he also has acetic acid. Now, acetic acid is one of those chemicals that has two hazards involved with it; one is it’s a corrosive of course, but the second is that it is a flammable. It has a flash point of about 100° Fahrenheit, which clearly makes it a flammable material, and it’s also a corrosive. Flammability is considered a more high risk than corrosivity; therefore, flammable organic acids in concentrated forms, it doesn’t matter if they are diluted, should be stored in the flammable cabinet. If you have any nitric acid, it needs to be stored separately from all other acids. Many of these acid cabinets will have a little special place to put the nitric acid. I don’t believe that there are any in this. I do see that there is acetylsalicylic acid stored in here; that’s aspirin, it’s not really a corrosive. Organic acids, particularly the high molecular weight ones aren’t corrosive in solutions, so it doesn’t need to be in here. It can be stored in the general storage. But, here again, you just need to go through each little bottle and container and put it on your sheet. Here he has sodium hydroxide stored in with the acids, which probably isn’t a good idea. It would be better if you don’t have a corrosive cabinet that’s dedicated to basic solutions; you should store them in general storage, not in the acid cabinet where they might react. Sometimes you’ll see how that happens when you store ammonium hydroxide and hydrochloric acid in the same cabinet, the fumes coming out even if you have the lids on tightly will react and make these crystal wigs-like on the bottles.
Part 6 – Labeling
Now, a little solution to the problem of things getting mis-shelved after you are through using them is to indicate what their proper category is by just little stickers that you put on the containers. Be sure to put it on the container and not the cap, because caps can get reversed and put on the wrong bottle. For example, this Scholar Chemistry, they have already done that for you. They have the green stripe; that means that is general storage. You can still put this on there so when you re-shelve these items after you’ve used them, you’ll know right where to put them. You might have yellow for the oxidizers; that’s the color that seems to be pretty standard, so we put that on there. Red or pink is as close as I could get, for flammable materials. Here’s this little bitty container of Phenolphthalein that is flammable, see it’s got the red there. But you want to see it really well, just put it on there, so that you’ll know that when you’re putting things back where they belong, you put them back where they belong.
Now occasionally, you will find a really old chemical, and they are the ones you need to pay careful attention to. I see one right here and I see that it is a harmless chemical, potassium bicarbonate. You can see by the antiquey looking label that it’s really old. There are a few tricks to making guesses as to how old. For example, the use of a zip code in an address was made mandatory in 1967. This address has no zip code, so we know it’s older than that; and here it says it was inventoried in 1968 so this is a very old chemical. But it’s harmless, potassium bicarbonate; it’s probably still good, but you might want to take it out of service. If you haven’t used it in 68 years, you’re probably not going to use it.
Another useful trick when you are putting these little stickers on the containers of material, is that if you know that this material is a regulated hazardous waste, and you can find that out by looking at EPA’s website. They have a list of materials that are hazardous waste, either because of their characteristic or because they are listed. So, they have two different categories, characteristic waste and listed waste. This would be a characteristic waste, because it is a strong oxidizer, so I would put a little sticker on there and just write “HW” or something to that sort. So that you know, when it comes time to dispose of it, that this is a regulated waste and you can’t dispose of it in the trash, you can’t put it down the drain; it has to be handled as a hazardous waste.
Part 7 – Classroom
You also need to look in the classroom to be sure there aren’t any chemicals stored here. It’s not a good idea ever to store any chemicals in a classroom, they should be returned to the storage area after the day’s experiment. A common place you might find chemicals in a classroom is in the teacher’s demonstration desk. Just go through all the drawers to make sure that something hasn’t been put in there inadvertently and forgotten about. Also, on the benches, they shouldn’t be left on the benches after the experiment. They should be put away promptly. Put them away, and then inventory them. And here again, look at all the drawers to see if some student has stashed something away where it doesn’t belong. This can take a long time. Here’s an example of a material that has been misplaced and could well be forgotten about. Fortunately, it’s not extremely toxic. Also, the fume hood is not a place to store chemicals. The fume hood is for doing procedures or experiments that require excellent ventilation. If you have materials up against the baffle in the back, it’s not going to be able to as efficient as it needs to be, so this is a very bad idea and should be highly discouraged. These materials should be inventoried and put away.
Remember to look high and low. I see some materials down here low on the floor; chemicals should never be stored on the floor. Fortunately, these are empty. Also, look high. You shouldn’t have to use a latter to check out these materials to see what’s in them to be sure there is no chemicals in them.
Don’t forget to check the refrigerator, make sure there are no chemicals stored in here; it’s a bad idea. Nothing in here, but somebody’s lunch, that’s good.
Part 8 – Disposal
After you’ve done your inventory you might have realized that perhaps you don’t need 15 pounds of potassium hydroxide, and you want to dispose of ten pounds of it. And you have found other chemicals that you just have too much of or you don’t use them anymore and you want to do away with them. So what can you do? The first thing that you need to do is determine what your status as a hazardous waste generator is. Most schools are what are called conditionally exempt small quantity generators. Hazardous waste management is regulated by a law called the Resource Conservation and Recovery Act of 1976, or RCRA for short. And it requires that generators of hazardous waste dispose of the waste properly and keep a record of the disposal of that waste. But since you are probably a conditionally exempt small quantity generator, the only requirement for you is to ensure that any hazardous waste is disposed of properly.
The definition of a conditionally exempt small quantity generator is a school that produces less than 100 kilograms of hazardous waste a month. Or, however, if you produce more than a kilogram of what is called P-listed waste in a month, then you are a large quantity generator. That’s another reason not to have any P-listed waste in your storage area. We have on DEP’s website; they do have a chart that will show you what P-listed waste might be in a laboratory are.
Also, a lot of the materials you have here are not hazardous at all, so they can be disposed of as ordinary trash. DEP also has on its website a school chemical clean out cheat sheet, which is a way that you can match up cations and anions that if a chemical contains these two then it is non-hazardous and can be disposed of as ordinary trash.
So, if you are conditionally exempt small quantity generator, there are several disposal options, at your disposal. You can give it away; ask other teachers if they could use this material in their classrooms or other schools in the district. Some school districts have an online inventory, where you can see what other teachers and other schools have before you buy a chemical. You can treat it, small quantity generators who are conditionally exempt are allowed to treat their waste. You can chemically destroy waste, and Flinn catalog has excellent ideas on how to dispose of small quantities of hazardous waste. You can evaporate a solvent if it’s a non-hazardous solvent, mostly water. It is not allowed to evaporate flammable solvents in order to dispose of them. Some substances can be poured down the drain, but you have to be very careful about doing that; some materials like chlorates, perchlorates, asides, and picrates can cause the formation of explosive salts in metal drains, so that should be avoided. Also, you have to meet the pretreatment standards of your sewage treatment plant, and that’s not easy to do. For example, the standard for copper going down the drain is eight parts per million and that is the equivalent of 10-4 molar solution of copper sulfate, which is not really a useful reagent in a high school. So, putting it down the drain should only be for non-hazardous materials. You can throw it in the trash if it is a non-hazardous item. Don’t just put it in the waste can, however. Put it in a box, mark the box “Non-hazardous school chemicals suitable for landfill disposal,” and put your name and number on it. It’s preferable if you hand deliver it to the landfill or to your local hazardous waste center.
For assistance in disposal of chemicals, contact the person in your county who is responsible for hazardous waste management. A list of these contacts is available on the SC3 page of DEP’s website
For more information about the SC3 program, several documents, including the chemical list I have mentioned, are available on DEP’s website, www.dep.state.fl.us . Just do a site search for SC3.
This notebook includes general information including list of especially hazardous chemicals.
Here is a how-to manual for chemical management in schools, and simple techniques for identifying unknown chemicals commonly found in schools.
We hope that this video has helped you plan and perform an inventory of your school’s chemicals; so that you can insure that they are being correctly stored, recognize imminent threat in high risk chemicals, note any chemicals in excessive amounts, or no longer being used. Please contact DEP for any needed assistance to ensure that your school provides a safe environment for you, your students, and your community.